Tire retreading equipment



P. E. HAWKINSON TIRE RETREADING EQUIPMENT Original Filed Nov. 29, 19445% m5 .7 V 7 5 z 5 a z M 3 4 4 w \\7\\ .5 3 fl April 8, 1947.

await. a, 1947 c TIRE RETBEADING EQUIPMENT Paul E. Hawkinson,Minneapolis, Minn., assignor to Paul E. Hawkinson Company, Minneapolis,Minn, a corporation of Minnesota Continuation of application Serial No.565,627. November 29, '1944. This application June 7, 1946, Serial No.675,064

1 Claim. (or 18-18) My invention relates to a novel structure to be usedparticularly in the retreading or vulcanizing of tires and wherein it isfound desirable or necessary to bring pressure on the sides of the tirein the form of, what is known in the tradeas, side plates. Side platesmay be used either for the purpose of relieving the side walls ofpneumatic tires from excess pressure or to force the peripheral treadportion of the tire against the mold or matrix with greater pressure. Itis understood that my invention may be utilized for either of the twoobjects sought to be attained.

It is the primary object of my invention to provide a highly eflicientand novel rim and side plate combination which may be constructed in aminimum of time and with a minimum of materials.

Another object of myinvention is the construction of a device of thekind described which can be used at a great saving of time to theoperator in the retreading or repairing of pneumatic tires.

The above and other objects will be apparent from the attached drawingsand the following specification. 1

Referrin to the drawings wherein like characters indicate like partsthroughout the several views:

Fig. 1 is a vertical axial section of my novel rim and side platestructure, shown as being mounted on a tire being retreaded; and

Fig. 2 is a side elevation of my novel structure.

Referring more particularly to the drawings, the numeral I indicates atire having an inner tube 2 and reinforced bead sections 3. The innertube 2 is shown as being provided with a valve stem 4.

Mounted on the peripheral outside surface of tire i is a one-piece tireretreading matrix 5, generally of the type disclosed in my earlierissued Patent 1,917,262 and consisting of a onepiece sheet metal matrix6 bent so as to provide laterally spaced confining flanges I and treaddesign forming ribs 8. On its outer side, sheet metal member 6 is shownas having acopper steam conducting tube 9 soldered or otherwise securedthereto, and wound in a spiral manner. Said sheet metal member 6 is alsoshown as bein provided with a plurality of metal reinforcing rings l0,preferably in the form of wire.

The new rubber being vulcanized to the crown of the tire i is indicatedby the numeral II.

An elongated tubular rim member i2 is shown as being provided with anaxial slot l3 extending from one end thereof to a point beyond the k 2center. The opposite end of said tubular member I2 is provided with anoutwardly turned re: taining flange It. The slotted end of tubular rimmember I! is provided at IS with threads which ,may extend inwardly anydesired distance, but

preferably, and as shown, extending inwardly about one-third of thelength thereof.

A pair of annular plate members I6 are adapted to fit loosely over thethreads i5 and one thereof is adapted to abut against flange M on theopposite end of said tubular rim member l2. other member l6, as shown,is retained in spaced relation so that each thereof comes in contactwiththe opposite sides of the tire casing placed therebetween, as shownin Fig. 1.

Centering rings I! are inserted between each annular plate member l6 andthe bead portions 3 of the tire. A knurled burr member i8 is shown ashavingscrew threaded engagement with the threads i5 of member i2.

Operation As indicated above, mold 5 is unbroken, and as shown, it is ofless diameter than the normal diameter of the tire. To enter the tireinto such a, mold it is recommended that the operator spread-the bedportions 3 apart at circumferentially spaced points so as to contractthe tire to a diameter less than that of the mold member 5, all as morespecifically disclosed and claimed 7 in my earlier patent Re. 21,956.

casing I and the casing is then dropped over the said tubular member sothat the valve stem 4 of tube 2 is in alignment with the slot l3- Beadmembers 3, as shown in Fig. 1, will come into contact with the spacer orcentering rings H. An equal number of spacer rings I! are then insertedloosely over the threaded members until they come to rest against theopposite bead; the other annular side plate It is then dropped looselyover the threaded tubular member l2; and the knurled burr i8 is screwedinwardly until suflleient pressure is brought to bear upon each side ofthe tire casing by the opposed annular plates l6.

Air is then inserted into the tire so as to expand the same with greaterforce against the matrix 5 The . sures exerted by such a tire.

3 and heat is introduced into the spiral steam coil or tube 9 so thatthe rubber I I is cured.

While I have shown my novel equipment as being used in conjunction withthe well known Hawkinson apparatus and method of retreading, it, ofcourse, does not follow that this particular combination of side platesand rim structure is confined in its use to such equipment and methods.In fact, it may well be used with any type of full-circle retreadingequipment with substantially equal benefit.

Furthermore, it should be obvious that y equipment is adaptable for usein any vulcanizing mold of full-circle construction wherein it isdesired to bring pressure against the side walls of the tire. a

The tire illustrated is one of small cross-sectional and overalldiameter, such as used on the tail wheels of cub and trainer airplanes.The apparatus illustrated is only of such construction as to beadequately strong to withstand the pres- However, this combination ofrim and side plate structure may be used with equal benefit on tires ofmuch greater cross-sectional and overall diameter, by merely increasingthe strength of the equipment used.

The simplicity and utility of the device is thought to be made obviousfrom the foregoing description and it will, of course, be understoodthat various alterations and changes in the details of construction andarrangement of parts may be made within the scope of the inventionherein disclosed and claimed.

This application is a continuation of application Serial No. 565,627.

What 1 claim-is:

A device for use in conjunction with a fullcircle tire retreading moldwhich comprises an I the bead portions of said tire, said plates and.spacer rings being removable from said tubular 1 member only from thethreaded end thereof, the threaded end of said tubular member having aslot which extends axially inwardly to a point more than half the lengthof said tubular member, and means engaging the threaded end of said rimmember for forcing said plates together and exerting equal force uponthe spaced side walls of said tire.

PAUL E. HAWKINSON.

REFERENCES ciTEn The following references are of record in th file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,836,850 Hudson Dec. 15, 19312,024,941 Miller Dec. 17, 1935 2,045,937 Woock June 30, 1936 2,115,349Taylor Apr. 26, 1938 2,124,345 Grange July 19, 1938 2,227,798

Rihn et al Jan. 7, 1941

